Portable valve-grinder.



fr. sENMAN.

PORTABLE VALVE GRINDER.

APPLICATION FILED SEPT. l0. HH?.

Patented Apr. 15,1919.

UNITED STATES PATENT OFFICE.

BROR F. STENMAN, OF WORCESTER, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO ALBERT W. LABSON, OF WORCESTER, MASSACHUSETTS.

PORTABLE VALVE-GRINDER.

Specification of Letters Patent.

Patented Apr. 15, 1919.

To all iti/0m it may concern Be it known that l, Buon F. STENMAN, a citizen of the United States, residing at iVoi'eester, in the county of Worcester and State of L'Iassachusetts, have invented a new and useful Portable Valve-Grinder, of which the following is a specification.

This invention relates to a valve grinder of the portable type, especially designed for grinding the inlet and exhaust valves of automobile and other gas engines.

ln the operation of grinding such valves it is found desirable to give eaoh valve a rapid reciprocating angular movement against. its valve seat.

Accordingly it is the general object of my present invention to provide a light, portable and convenient mechanism effective to thus rapidly reciprocate a valve angularly.

My improved valve grinder in portable form comprises a small rotary motor, preferably electric, a crank pin or other eccentric device driven through reduction gearing from said motor, an operating shaft adapted to engage the valve head, and connections from the eccentric device to the operating shaft effective to transform the continuons movement of the eccentric device into a reciprocating movement of the operating shaft.

My invention further relates to certain arrangements and combinations of parts hereinafter described and more particularly pointed out in the appended claims.

A preferred form of my invention is shown in the drawings in which- Figure l is a front elevation of my improved valve grinder;

Fig. 2 is a partial sectional elevation thereof;

Fig. 3 is a sectional plan view taken along the line 3-3 in Fig. 2, and

lF ig. 4 is a detail plan view showing certain of the parts appearing in Fig. 3, but in a different position.

. Referring to the drawings, my improved valve grinder comprises a. casing formed in two parts, the upper portion l inolosing the operating motor and the lower portion 11 inclosing the operating shaft and the connections to said operating shaft. A cap may also be detacliably fitted over the upper end of the easing 10, said cap being provided with a handle 10".

The motor may be of any common rotary type and is herein shown as an electric motor having an armature 12 mounted upon an armature shaft 13 having its bearings in the casing 10. The shaft 13 extends through the lower end of tlhe casing and is provided at its outer end with a pinion 14 engaging a gear 15 loosely mounted upon a stud 1G fixed in the easing 10. A second pinion 17 is secured to the gear 15 and rotates therewith upon the stud 16. The pinion 17 meshes with a gear 18 loosely mounted upon an extension of the shaft 13.

An operating shaft 20 is mounted in bearings in a hub 21 forming a downward extension of the casing member 11, and at its lower end is provided with a slotted clamping device having a binding screw 23 by means of which the jaws of the clamping device may be caused to grip devices 2li for engaging the head of the valve to be ground. These devices 24 may be readily removed and replaced by engaging devices of a different type when desired.

The shaft 2() is provided with an offset arm 25 pivo-tally connected at 2G to a link The opposite end of the link 27 is pivoted at 28 to one arm of a `loell crank 29 which mounted upon a pivot 30 fixed in the casing member 11. The second arm of the bell crank 29 is connected at, 31 to one end of a link 32 and the opposite end of the link 32 is pivot-ally mounted on a screw or stud 33 eceentrically secured in the lower face of the gear 18. The stud 33 thus acts as a crank pin or eccentric for moving the link 32.

With these connections it will be evident that continuous rotar movement of the armature 12 will pr uce a corresponding rotary movement` of the gear 18 but at reduced speed. The eccentric stud or crank pin 33 is thus moved in a circular path and becomes effective through the link 32, the bell crank 29 and the link 27 toswing tllie arm 25 alternately from the position shown in Fig. 3 to that shown in Fig. 4 and vice versa. Continuous rotary movement of the armature is thus transformed into a rapid reciprocating angular movement of the operating shaft 20, and a valve engaged by said shaft will be rapidly reciprocated upon its valve seat.

The device is of light weight and small size and may receive power from any ordinary electric light socket. By the use of this device the valve grinding operation may be performed with great rapidity, and with a minimum amount of labor. The mechanical parts are of simple construction and the device is convenient and reliable in operation.

Having thus described my invention it will be evident that changes and modi cations can be made therein by those skilled in the art within the spirit and scope of my invention as set forth in the claims. Therefore I do not wish to be otherwise limited to the details herein disclosed, but what I claim 1s:-

1. A portalble valve grinder having, in combination, a reciprocating operating shaft provided with devices for engaging a valve head, an arm on said shaft, a bell crank, a link connecting said arm to said bell crank, a crank pin, a second link connecting Said bell crank to said crank pin, a rotatable support for said crank pin axially alined With .said operating shaft, and means to continu ously rotate said support, thereby reciprocating said shaft angularly.

Q. A portable valve grinder having, in combination, a casing, a reciprocating operating shaft mounted therein, devices on .said shaft for engaging a valve head, a motor in said casing, upper and lower bearings for maid motor, an eccentric device movable in a circular path by Said motor, operative connections from said eccentric to said shaft effective to reciprocate said shaft angularly, and a cap inclosing the upper end of said casing and independent of the upper motor bearing, said cap being detachably mounted on the upper end of said casing and comprising a handle for convenient manipulalion of said valve grinder.

In testimony vvhereoiI I hereunto affix my signature.

BROR F. UTENMAN.

Uopiel of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, IJ. C. 

